Connection network for the adjustable connection of a PLA

ABSTRACT

Circuit arrangements (ULB) can be connected to one another with the assistance of a connection network (VN). Every circuit arrangement (ULB) can thereby operate as transmitter or as receiver. The connection network (VN) contains a matrix that is composed of a connection matrix and of an adjustment matrix. In the connection matrix, the data lines (DL) leading to the circuit arrangements (ULB) cross with coupling lines, whereby switching elements are arranged at the crossing locations. The adjustment matrix is composed of adjustment lines that cross with the coupling lines, whereby switching elements are arranged at the crossing locations. The connections between the data lines can be determined by programming the switching elements in the connection matrix and in the adjustment matrix and by applying an adjustment code to the adjustment matrix. The assistance of control signals can thereby be used to determine whether the data lines represent a data input or a data output.

BACKGROUND OF THE INVENTION

The invention is directed to a connection network for adjustableconnection of circuit arrangements, particularly programmable circuitarrangements, whereby every circuit arrangement can be transmitter orreceiver. It is to be understood that the term "circuit arrangement" asused herein refers to a circuit element such as a programmable logicarray (PLA).

It is required for some applications that a plurality of circuitarrangements be capable of being adjustably connected to one another.Each of these circuit arrangements can thereby be transmitter orreceiver. This can be the case when a plurality of programmablecircuits, abbreviated as PLA, are combined in a sequential logic system.Such programmable circuits contain an AND level and an OR level. Theoperation of the input signals in accord with a function table stored inthe AND level ensues in the AND level. These operation results of theAND level that are also referred to as product terms, are supplied tothe OR level and are operated there according to the function tablecontained in the OR level to form what are referred to as sum terms. Thesum terms are output at the outputs of the OR level. Such a PLA hasinput lines that lead to the AND level and output lines that lead outfrom the OR level available to it. The structure of a programmablecircuit arrangement can also be such that the AND level and the OR levelare combined and it is possible to define by programming whether thelines leading into the programmable circuit arrangement--referred to asdata lines in future--should be input lines or output lines.

SUMMARY OF THE INVENTION

The object underlying the invention is comprised in specifying aconnection network for the adjustable connection of circuit arrangementsthat operate either as transmitter or as receiver. In a connectionnetwork of the species initially recited, this object is achieved inaccord with the characterizing of patent claim 1.

The connection network is based on the principle of the bidirectionalPLA, i.e. on the principle of a programmable circuit arrangement,whereby the lines employed as data lines can be set both as input lineas well as output line with the assistance of a control signal. Theconnection of the data lines within the connection matrix ensues withthe assistance of the adjustment matrix.

The advantage of this connection network is to be seen therein thatevery data line can be connected to every data line by programming theswitching elements in the matrix in accord with a connection table and,moreover, the direction of the data transmission can be defined.

BRIEF DESCRIPTION OF THE DRAWINGS

Other improvements of the invention derive from the subclaims. Theinvention shall be set forth further with reference to exemplaryembodiments that are shown in the figures. Shown are:

FIG. 1 a block circuit diagram of the connection network for connectingfour circuit arrangements;

FIG. 2 a further block circuit diagram of the connection network;

FIG. 3 a fundamental circuit diagram of the matrix employed in theconnection network;

FIG. 4 a wiring diagram of the matrix;

FIG. 5 and FIG. 6 examples of a programmed matrix;

FIG. 7, 8 examples of the connection setup between two circuitarrangements;

FIG. 9, 10 further examples of the connection of circuit arrangementswith the assistance of the connection network.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 yields a block circuit diagram wherein four circuit arrangementsULB1 through ULB4 can be connected to one another via a connectionnetwork VN. Bidirectional, programmable circuit arrangements can beprovided, by way of example, as circuit arrangements ULB. Theseprogrammable circuit arrangements have lines on which signals X aresupplied or taken and have terminals A that are to be connected to oneanother via the connection network VN. Data transmission lines thereforelead from the terminals A of the programmable circuit arrangements ULBto the connection network VN. The connection network VN is constructedsuch that these lines can be connected to one another in the connectionnetwork and such that the direction of the data transmission can be set.This means that the signals a on the data transmission lines between theprogrammable circuit arrangements ULB and the connection network VN canbe adjustably transmitted in the one direction or in the oppositedirection.

FIG. 2 shows a block circuit diagram of the connection network VN. Thiscan be composed of a matrix MA and of a monitoring circuit US. The coreof the connection network VN is thereby the matrix MA. This is composedof a connection matrix V-MA and of an adjustment matrix E-MA. The datatransmission lines lead into the connection matrix V-MA as data lines DL1 through DLn (n=1 . . . ). The direction of the transmission of thesignals a on the data lines DL is determined with the assistance of acontrol signal STl through STn. The connection between the data lines DLis realized inside the connection matrix V-MA. This connection betweenthe data lines DL is influenced with the assistance of the adjustmentmatrix E-MA. The adjustment matrix E-MA is supplied with adjustmentsignals Ml through Mn that determine the connections between the datalines DL with the assistance of the adjustment matrix E-MA.

The assistance of a monitoring means US that can be additionallyprovided makes it possible to check whether the connection setup isfaulty or not.

The structure of the matrix MA shall be set forth in greater detail withthe assistance of FIG. 3. The matrix MA is composed of the connectionmatrix V-MA and of the adjustment matrix E-MA. The connection matrixV-MA is constructed of crossing data lines DL and of coupling lines KL;the adjustment matrix E-MA is constructed of crossing adjustment linesMD and of the coupling lines KL. It is advantageous for programming thematrix MA when the data lines DL branch into two matrix lines ML perdata line DL and, correspondingly, the adjustment lines MD branch intorespectively two adjustment sub-lines MDL. Respectively two connectionpossibilities thereby respectively arise per interconnect locationbetween a data line or, respectively, adjustment line and a couplingline KL.

The direction of the transmission of data a on the data lines DL isdetermined with the assistance of control signals ST that are conductedto an input circuit EG arranged in the data line.

A realization of the matrix can be derived from FIG. 4. It derives fromFIG. 4 that switching elements KE are arranged at the interconnectlocations, each of these switching elements KE being respectivelycomposed of two logic elements SE1, SE2. These logic elements SE aredisconnectable. For example, they can be composed of a diode D and of afuse F that can be blown. With two switch elements per switching elementKE, three statuses can be stored, for example a binary 1, a binary 0 anda third status. For example, the binary 1 can be stored when the logicelement SE1 between the matrix line ML1 and a coupling line KL is notdisconnected but, by contrast, the logic element SE2 between the matrixline ML2 and the coupling line KL is disconnected. A binary 0 is storedwhen the logic element SE2 between the matrix line ML2 and the couplingline KL is not disconnected but, by contrast, the logic element SE1between the matrix line ML1 and the coupling line KL is disconnected.The third status is stored when both logic elements SE1, SE2 aredisconnected.

The matrix lines ML1, ML2 are connectable either to the operatingvoltage source VS via a resistor R2 or to the operating voltage sourceVC via a resistor R3. VS can be 5 volts; VC can be 0 volts. Theswitching can ensue with the assistance of a switch over means AB. Theswitching ensues dependent on the control signal ST. When the controlsignal is such that a data line DL is connected as input, i.e. the dataterminal AS is a data input, and, thus, driver stages T1, T2 can bedriven conductive, then the matrix lines ML are connected to theoperating voltage source VS. When, however, a data line DL is to beoperated as output dependent on the control signal ST, then the driverstages T1 and T2 are turned off and a driver stage T3 that waspreviously turned off is switched on. The matrix lines ML must then beconnected to the operating voltage source VC.

The coupling lines KL are connected to the first operating voltagesource VS via a resistor R1.

The adjustment matrix E-MA is constructed corresponding to theconnection matrix V-MA. However, the adjustment sub-lines MDL areconnected only to the operating voltage source VS via the resistor R2.Driver stages T4, T5 likewise lie in the adjustment sub-lines MDL.

There is an adjustment code for every desired connection possibilitybetween the data lines DL, this adjustment code proceeding to theadjustment matrix E-MA via the adjustment terminals El through Em. Forprogramming, a connection table is set up in the following way for thatpurpose:

The plurality of necessary adjustment terminals E is log 2 (plurality ofadjustment possibilities).

One column in the connection matrix is provided for every data terminalAS and for every adjustment terminal E.

An adjustment code is defined for every adjustment possibility.

The possible bit combinations at the data terminals AS are defined forevery adjustment possibility; one row in the connection table is neededfor every bit combination.

The connection table is subsequently minimized.

This shall be set forth with reference to an example: A connection tablefor a connection network VN having four data terminals AS1 through AS4is to be realized. In the first adjustment possibility, AS1 should beconnected to AS2 and AS3 should be connected to AS4. In the secondadjustment possibility, AS1 should be connected with AS2, AS3, AS4. Onlya single adjustment terminal E is then required since there are only twopossibilities. The signals at the data terminals AS are referenced a1through a4; the signal at the adjustment line is referenced ml. Theconnection table then looks like this:

    ______________________________________                                        al,        a2,   a3,         a4, ml.                                          ______________________________________                                        0          0     0           0   0                                            0          0     1           1   0                                            1          1     0           0   0                                            1          1     1           1   0                                            0          0     0           0   1                                            1          1     1           1   1                                            ______________________________________                                    

There is a connection between the data terminals AS1 to AS2 and betweenthe data terminals AS3 and AS4 in the first four rows of the connectionmatrix. The data terminal AS1 is connected to AS2, AS3 and AS4 in thelast two rows of the connection matrix.

The programming of the matrix MA corresponding to this connection tablecan be derived from FIGS. 5 and 6. The rows of the connection table arethereby stored in the columns of the matrix or the columns of theconnection table are realized in the rows of the matrix. The assistanceof a dash is used to indicate whether a connection exists between a dataline or adjustment sub-line and a coupling line. Let the programming beset forth with reference to the data line DL1 and with reference to theadjustment line MD1. In accord with the connection matrix for a1, thefollowing programming is provided for the data line DL1: 0 0 1 1 0 1. Aconnection between the matrix line ML12 and the allocated coupling lineis respectively provided given a binary 0; a connection between thematrix line ML11 and a coupling line KL is provided given theprogramming of a binary 1. The corresponding case also applies to theadjustment line MD corresponding to the column of the connection matrixfor ml. The programming is corresponding 0 0 0 0 1 1.

FIG. 5 indicates the transmission of the data via the data line DL giventhe condition that the adjustment code is binary 0. Let a binary 0 besupplied to the data line DL1 connected as input; let a binary 1 besupplied to the data line DL3 connected as input. A binary 0 is then seton the coupling line KL1 because of a3; a binary 1 is then set on thecoupling line KL2 because of a3; a binary 0 is set on the coupling lineKL3 because of a1; a binary 0 is set on the coupling line KL4 because ofa1; and a binary 0 is set on the coupling lines KL5 and KL6 because ofml. A binary 0 appears on the data line DL2 connected as output sincethe binary 1 on the coupling line KL2 cannot proceed to the output AS2.A binary 1, by contrast, appears on the data line DL4 since the binary 1on the coupling line KL2 can proceed to the output AS4.

The explanation of the function shows that a binary 0 on one of thematrix lines ML or adjustment sub-line MDL penetrates via a logicelement SE to the coupling line KL. Inversely, a binary 1 on a couplingline KL penetrates to the data lines D1 connected thereto when thesedata lines are connected as output.

The function of the connection table shall be set forth once again withreference to a second exemplary embodiment shown in FIG. 6. Let theadjustment code now be binary 1. When the data line DL1 that isconnected as input is supplied with a binary 1, then binary 0 isestablished on the coupling lines KL1 through KL5 and a binary 1 isestablished on the coupling line KL6. In accord with the programming,the binary 1 on the coupling line KL1 penetrates to all [data lines] DL2through DL4 connected as output, so that the output signal a2 through a4is binary 1. The binary 1 is thus transmitted from the data lines DL1onto the data lines DL2, DL3 and DL4.

The assistance of the adjustment code can thus be used to determinewhich data lines DL are connected to one another. The direction of thedata transmission, by contrast, is determined with the assistance of thecontrol signal ST. The following Table 2 shows when a data terminal AScan be input or output:

    ______________________________________                                        ml         ASl   AS2          AS3 AS4                                         ______________________________________                                        0          E     A            E   A                                           0          A     E            E   A                                           0          E     A            A   E                                           0          A     E            A   E                                           1          E     A            A   A                                           1          A     E            A   A                                           1          A     A            E   A                                           1          A     A            A   E                                           ______________________________________                                    

The adjustment code thus sets the internal connections between the datalines DL. The control line ST sets the data direction on the data lines.Only one data line that is connected as input dare be connected to datalines that are connected as output. Some other connection is notallowed. Given unallowed connection set up, the monitoring means USactivates a signal connection fault FB. FIG. 7 shows a connectionbetween a circuit arrangement ULB and the connection network VN. Whenthe data transmission line DUL in the ULB is switched as input, then itmust be switched as output in the connection network VN. When the datatransmission line DUL in the ULV is set as output, then it must beconnected as input in the connection network VN. The allowed connectionsare stored in the monitoring means US in a ROM, RAM or PLA. The allowedconnections are recited in Table 2 that has already been shown above.

When it is assured that no unallowed connections occur, then themonitoring means US can be omitted. For example, this is the case whenan instruction decoder BD in which the allowed connections are stored isprovided in accord with FIG. 8.

Further examples of connection networks comprising four circuitarrangements ULB derive from FIGS. 9 and 10. The connection network ofFIG. 9 provides respectively two data transmission lines DUL betweenevery ULB and the connection network VN. Each of these data transmissionlines can be connected to each data transmission line of a differentcircuit arrangement via the connection network VN. FIG. 10 yields anetwork composed of a plurality of connection networks, whereby everyconnection network respectively collaborates with four circuitarrangements ULB. The circuit arrangements ULB can be interconnected toform a cube, whereby a connection network is arranged in every diagonalintersection of every corner of the cube.

The invention is not limited to the particular details of the apparatusdepicted and other modifications and applications are contemplated.Certain other changes may be made in the above described apparatuswithout departing from the true spirit and scope of the invention hereininvolved. It is intended, therefore, that the subject matter in theabove depiction shall be interpreted as illustrative and not in alimiting sense.

we claim:
 1. Connection network for the adjustable connection of circuitelements, particularly programmable circuit elements, whereby everycircuit element can be a transmitter or receiver, comprising:a matrixcomposed of a connection matrix and of an adjustment matrix; theconnection matrix composed of bidirectionally operable data lines and ofcoupling lines crossing therewith and having programmable switchingelements respectively connected between the data lines and the couplinglines at the crossing locations of the data lines and coupling lines;data terminals of the data line connected to terminals of the circuitelements; the adjustment matrix composed of the coupling lines and ofadjustment lines crossing therewith and having programmable switchingelements respectively connected between the coupling lines andadjustment lines at the crossing locations of the coupling lines andadjustment lines; data terminals being connected to one another withinthe connection matrix by applying an adjustment code to the adjustmentlines of the adjustment matrix.
 2. Connection network according to claim1, wherein the switching elements are disconnectable switch elementseach of which is respectively coupled between a data line or,respectively, an adjustment line and a coupling line.
 3. Connectionnetwork according to claim 2, wherein an input circuit is coupled inevery data line, a control signal being received by the input circuitthat controls driver stages located in the input circuit such that theassociated data terminal represents either a data input or a dataoutput.
 4. Connection network according to claim 3, wherein each dataline branches into first and second matrix lines, whereby the inputcircuit is composed of a first drive stage connected to the first matrixline, of a second, inverting driver stage connected to the second matrixline and of a third driver stage having an input connected to an outputof the first driver stage and an output connected to inputs of the firstand second driver stages and wherein every driver stage can bedisconnected by the control signal.
 5. Connection network according toclaim 2, wherein every adjustment line branches into two matrix lineswhereof the one receives an adjustment signal and the other receives theadjustment signal inverted.
 6. Connection network according to claim 4,wherein each switching element per data line has two switch devicesconnected between the first and second matrix lines allocated to thedata line and the coupling lines, respectively, and being programmedaccording to a connection table.
 7. Connection network according toclaim 6, wherein a non-disconnected switch device is coupled between onematrix line and a coupling line for programming a binary logic 1 and anon-disconnected switch device is coupled between the other matrix lineand the coupling line for programming a binary logic
 0. 8. Connectionnetwork according to claim 7, wherein only disconnected switch devicesare coupled between the first and second matrix lines of a data line anda coupling line for programming a third status different from a firststatus of the logic 1 and from a second status of the logic
 0. 9.Connection network according to claim 5, wherein when operating a dataline as input, the allocated matrix lines are connected to a firstoperating voltage source via a resistor and, given operation as output,the allocated matrix lines are connected to a second operating voltagesource via a resistor.
 10. Connection network according to claim 9,wherein the coupling lines are connected to the first operating voltagesource via a resistor.
 11. Connection network according to claim 1,wherein a monitoring means is additionally provided in which allowedconnections between the data terminals are stored and is connected tothe lines for the control signals and for the adjustment code. 12.Circuit arrangement according to claim 1, wherein a plurality ofconnection networks are provided, being respectively connected to aplurality of circuit elements.
 13. Connection network according to claim5, wherein each switching element per adjustment line has two switchdevices connected between the first and second matrix lines allocated tothe adjustment line and the coupling lines, respectively and beingprogrammed according to a connection table.
 14. Connection networkaccording to claim 13, wherein a non-disconnected switch device iscoupled between one matrix line and a coupling line for programming abinary logic 1 and a non-disconnected switch device is coupled betweenthe other matrix line and the coupling line for programming a binarylogic 0.